CN1269973C - Warm up method of combustion supporting air through coal gas from blast furnace hot blast stove in high temperature - Google Patents

Abstract

The invention provides a method for preheating hot blast stove gas and combustion-supporting air of a high-blast furnace, which is characterized in that: using one inorganic heat transfer heat exchanger, the hot blast stove and the small-scale high-efficiency heat storage The blast furnace gas is preheated to 170-190°C by the type combustion device; the blast furnace gas of 170-190°C is burned by a pair of small-scale high-efficiency regenerative combustion devices automatically controlled by computers, and the combustion-supporting air of the hot blast stove is preheated to 1050-1100°C . Therefore, it is ensured that the temperature of the hot air in the hot blast stove reaches 1300-1350°C. Its advantages are: less preheating system equipment, high temperature air precooking equipment, long life, high efficiency, small size, computer automatic control, saving precious coke oven gas with high calorific value, only burning surplus blast furnace gas with low calorific value, making the air of the hot blast stove The temperature reaches the international advanced level of 1300-1350 ℃, which can reduce the ton iron-coke ratio by 60-70kg, increase the amount of coal injection by 100-120kg, increase iron production by 9-10.5%, and recover the investment in about one year.

Description

A method for preheating hot blast stove gas and combustion-supporting air of high blast furnace

technical field

The invention belongs to the technical field of blast furnace gas preheating, and in particular provides a method for preheating high blast furnace hot blast stove gas and combustion-supporting air.

Background technique

With the large-scale blast furnace, blast furnace ironmaking technology is developing in the direction of high efficiency, longevity, high blast temperature, and large coal injection volume. Raising the air temperature is beneficial to blast furnace production, which can reduce the coke ratio, increase the amount of coal injection, increase the output and reduce the production cost. High air temperature technology has been widely used in major steel-producing countries in the world. At present, the average wind temperature of large blast furnaces in Europe and Japan has reached 1250°C, and is heading towards 1300-1350°C. However, the average air temperature of blast furnace hot blast stove in my country is only about 1000°C. Overseas high wind temperature technology mainly adopts the method of burning high-quality gas and preheating both air and gas. Coke oven gas with high calorific value is very precious in most domestic iron and steel enterprises, and blast furnace gas with low calorific value is surplus. Therefore, the high blast temperature technology of blast furnace hot blast stove in my country can only use the high temperature flue gas produced by burning blast furnace gas and the low temperature flue gas of hot blast stove as heat source, and the method of preheating gas and combustion air. For example, the Chinese patent application CN1084792C "Method for preheating air and gas of blast furnace hot blast furnace with high blast temperature" disclosed the following technical scheme on May 15, 2002: using 3 heat pipe heat exchangers, using 280-320 ℃ hot blast stove flue gas to simultaneously For the hot blast furnace, the air and blast furnace gas are preheated to 130-150°C for the first time; then, two heat pipe heat exchangers are used to transfer the high-temperature flue gas of 900-1000°C produced by the flue gas generator to the air successively. Perform second preheating with blast furnace gas to preheat air to 400-450°C and blast furnace gas to 300-350°C. Under the condition of fully burning blast furnace gas, the air supply temperature reaches 1250-1310°C. The problem that this technical scheme exists is:

(1) The preheating system has a large number of equipment and pipelines, is bulky, and occupies a large area and space. The two preheatings share 5 heat pipe heat exchangers and 1 flue gas combustion furnace. The site of the blast furnace hot blast stove is crowded, and various pipelines are staggered in the air. Therefore, this technical scheme has great limitations as being put into practice, and so many preheating equipment and pipelines cannot be placed on the spot of many blast furnace hot blast stoves.

(2) The heat dissipation area of the preheating system equipment and pipeline is large, and the heat dissipation loss is large.

(3) The heat pipe heat exchanger is still used for the second preheating, which is not the best choice. Under high temperature conditions, metal heat exchangers have short life, bulky volume, low temperature efficiency and thermal efficiency. A long-life, high-efficiency, and small regenerative combustion device should be used.

Contents of the invention

The object of the present invention is to provide a method for preheating blast furnace hot blast stove gas and combustion-supporting air, which only burns blast furnace gas to further increase the blast temperature of blast furnace hot blast stove to the international advanced level of 1300-1350°C; high-temperature preheating equipment is preferred, Reduce the number of preheating system equipment and pipes, floor area, occupied space and heat dissipation loss, and improve temperature efficiency and thermal efficiency.

Technical scheme of the present invention is:

Use 1 inorganic heat transfer heat exchanger to preheat the hot blast stove and small high-efficiency regenerative combustion device to 170-190 ℃ with the flue gas of the hot blast stove at 280-320 ℃; use a pair of computer-controlled small The high-efficiency regenerative combustion device burns blast furnace gas at 170-190°C, and preheats the combustion-supporting air of the hot blast stove to 1050-1100°C.

The composition of the present invention is: use one inorganic heat transfer heat exchanger, use the flue gas of the hot blast stove at 280-320 ℃ to preheat the blast furnace gas to 170-190 ℃ for the hot-blast stove and the small-scale high-efficiency regenerative combustion device; 2). Use a pair of computer-controlled small regenerative combustion devices to burn blast furnace gas at 170-190°C, and preheat the combustion-supporting air of the hot blast stove to 1050-1100°C. The specific process is:

As shown in FIG. 1 , an inorganic heat transfer heat exchanger 1 used for preheating blast furnace gas in the present invention is arranged on the flue gas pipe Y leading to the chimney 2 from the hot blast stove 9 . The flue gas temperatures of the hot blast stove entering and exiting the inorganic heat transfer heat exchanger 1 are respectively 280-320°C and 150-160°C. The blast furnace gas preheated to 170-190° C. is sent to the hot blast stove 9 and the burner of the small-scale high-efficiency regenerative combustion device 4 respectively through the blast furnace gas pipeline G.

The combustion-supporting air of the small-scale high-efficiency regenerative combustion device 4 is supplied to the burner through the blower 3 and the air pipe K, and the coke oven gas used for ignition of the burner is supplied through the pipe J. The ignition burner for burning coke oven gas is equipped with a high-voltage electric ignition device and an ultraviolet photosensitive flame detection device to ensure the safety and reliability of the automatic control of the blast furnace gas ignition and combustion process. The preheated 170-190°C blast furnace gas burns with air in the high-speed burner or sub-high-speed burner of the small high-efficiency regenerative combustion device, and the high-temperature flue gas generated rotates at high speed in the space above the regenerator, and then the Evenly distributed into the heat storage pebble bed, after efficient heat exchange with ceramic balls, the flue gas at 150-160 °C is discharged through the reversing mechanism 5 and the induced draft fan 6. The combustion-supporting air of the hot blast stove enters the regenerator of the small-scale high-efficiency regenerative combustion device 4 through the blower 7 and the reversing mechanism 5, is heated to 1050-1100°C by the ceramic ball, and is sent to the combustion chamber of the hot blast stove through the hot blast valve 8 and the hot blast pipeline R . The small high-efficiency regenerative combustion device is automatically controlled by the computer, so it can ensure that the blast furnace hot blast stove air temperature reaches 1300-1350 °C under the condition of only burning blast furnace gas. Among them, the regenerator of the small-scale high-efficiency regenerative combustion device is a high-alumina and high-silicon ceramic ball with a diameter of 10-30 mm.

The computer automatic control of the small high-efficiency regenerative combustion device of the present invention includes: 1 automatic switching program control of the small high-efficiency regenerative combustion device, combustion control, heat storage control, combustion device vault temperature control, exhaust gas temperature control etc.

The present invention has the advantages of less preheating system equipment, high temperature air preheating equipment with long life, high efficiency, small size, computer automatic control, saving precious coke oven gas with high calorific value, and only burning surplus blast furnace gas with low calorific value, so that the hot blast stove The wind temperature reaches the international advanced level of 1300-1350℃, which can reduce the iron-coke ratio per ton by 60-70kg, increase the amount of coal injection by 100-120kg, increase iron production by 9-10.5%, and recover the investment in about one year.

The invention makes the air supply temperature of the blast furnace hot blast stove reach 1300-1350 DEG C, which is 50 DEG C higher than the 1250-1310 DEG C of the prior art (CN1084792C). However, the number, volume, floor area, occupied space, and heat dissipation loss of the equipment and pipelines used in the present invention are greatly reduced, and only one inorganic heat transfer heat exchanger is used for low-temperature preheating to fully utilize the low-temperature flue gas waste heat of the blast furnace hot blast stove resources, and the exhaust gas temperature is only about 160°C, while the low-temperature preheating in the prior art (CN1084792C) uses three heat pipe heat exchangers, and the exhaust gas temperature is about 170°C. High-temperature preheating, the present invention applies modern high-temperature air combustion technology and theory, uses a pair of small, high-efficiency, long-life, computer-automatically controlled regenerative combustion devices, and burns blast furnace gas at 170-190°C directly in the high-efficiency regenerative chamber Preheat the combustion-supporting air to 1050-1100°C, while the prior art (CN1084792C) uses traditional combustion technology and preheating methods, using 3 sets of thermal equipment separated from each other, that is, 2 sets of short-lived and bulky metal heat exchangers at high temperatures Heater, and a flue gas burner to preheat air and gas for the second time, its temperature efficiency and thermal efficiency are not high. Compared with the two, the present invention has obvious advantages.

Description of drawings

Fig. 1 is a process system diagram of the present invention. Among them, the inorganic heat transfer heat exchanger 1, the chimney 2, the blower 3, the small-scale high-efficiency regenerative combustion device 4A, B, the reversing mechanism 5, the induced draft fan 6, the blower 7, the hot air valve 8, Hot blast stove 9 comprises totally 4 seats of №1, №2, №3, №4.

Detailed ways

One inorganic heat transfer heat exchanger 1 is arranged on the flue gas pipe Y leading to the chimney 2 from the hot blast stove 9 . The flue gas temperatures of the hot blast stove entering and exiting the inorganic heat transfer heat exchanger 1 are respectively 300°C and 160°C. The blast furnace gas preheated to 180° C. is sent to the hot blast stove 9 and the burner of the small-scale high-efficiency regenerative combustion device 4 respectively through the blast furnace gas pipeline G.

The combustion-supporting air of the small-scale high-efficiency regenerative combustion device 4 is supplied to the burner through the blower 3 and the air pipe K, and the coke oven gas used for ignition of the burner is supplied through the pipe J. The ignition burner for burning coke oven gas is equipped with a high-voltage electric ignition device and an ultraviolet photosensitive flame detection device to ensure the safety and reliability of the automatic control of the blast furnace gas ignition and combustion process. The preheated 180°C blast furnace gas burns with air in the high-speed burner or sub-high-speed burner of the small high-efficiency regenerative combustion device, and the high-temperature flue gas generated rotates at high speed in the space above the regenerator, and then the airflow is evenly distributed The ground enters the heat storage pebble bed, and the flue gas at 160°C is discharged through the reversing mechanism 5 and the induced draft fan 6 after efficient heat exchange with the ceramic balls. The combustion-supporting air of the hot blast stove enters the regenerator of the small-scale high-efficiency regenerative combustion device 4 through the blower 7 and the reversing mechanism 5, is heated to 1070°C by ceramic balls, and is sent to the combustion chamber of the hot blast stove through the hot blast valve 8 and the hot blast pipe R. The small high-efficiency regenerative combustion device is automatically controlled by a computer, so it can ensure that the blast furnace hot blast stove air temperature reaches 1340°C under the condition of only burning blast furnace gas. Among them, the regenerator of the small-scale high-efficiency regenerative combustion device is a high-alumina and high-silicon ceramic ball with a diameter of 20mm.

Claims (3)

1, a kind of high-blast-temperature hot-blast stove coal gas, combustion air pre-heating mean, it is characterized in that: use 1 inorganic heat transfer interchanger, hotblast stove and small-sized efficient heat accumulating burner capable burning blast furnace gas are preheating to 170～190 ℃ with 280～320 ℃ hot-blast stove fumes; Blast furnace gas with 170～190 ℃ of 1 pair of computer-controlled small-sized heat accumulating burner capable burnings is preheating to 1050～1100 ℃ with the hotblast stove combustion air; The heat storage of small-sized efficient heat accumulating burner capable is that diameter is the high siliceous Ceramic Balls of high alumina of 10～30mm, the combustion air of small-sized efficient heat accumulating burner capable (4) infeeds burner through gas blower (3) and air line K, the burner igniting is infeeded by pipeline J with coke-oven gas, use igniter burner assembling high voltage electric portfire, the UV photosensitive flame detecting device of coke-oven gas, control is safe and reliable automatically to guarantee blast furnace gas ignition process; High combustion rate burner or inferior high combustion rate burner and the air combustion of 170～190 ℃ blast furnace gas in the small-sized efficient heat accumulating burner capable through preheating, the high-temperature flue gas that is produced is at regenerator superjacent air space high speed rotating, air-flow enters the heat-storing sphere bed with being evenly distributed then, after carrying out high efficient heat exchanging with Ceramic Balls, 150～160 ℃ flue gas is discharged through reversing mechanism (5) and induced draft fan (6); The hotblast stove combustion air is heated to 1050～1100 ℃ through the regenerator that gas blower 7 and reversing mechanism (5) enter small-sized efficient heat accumulating burner capable (4) by Ceramic Balls, delivers to the Combustion of Hot Air Furnace chamber through hot blast valve (8) and hot air duct R; Therefore the small-sized efficient heat accumulating burner capable can guarantee that under a burning blast-furnace gas condition, the blast funnace hot blast stove wind-warm syndrome reaches 1300～1350 ℃ by computer controlled automatic.

2, pre-heating mean according to claim 1, it is characterized in that: used 1 the inorganic heat transfer interchanger (1) of described preheating blast furnace gas is arranged in hotblast stove (9) and leads on the flue Y of chimney (2), hot-blast stove fume temperature into and out of inorganic heat transfer interchanger (1) is respectively 280～320 ℃ and 150～160 ℃, is preheating to 170～190 ℃ blast furnace gas is sent into hotblast stove (9) and small-sized efficient heat accumulating burner capable (4) respectively through blast furnace gas pipeline G burner.

3, pre-heating mean according to claim 1 is characterized in that: the content of described small-sized efficient heat accumulating burner capable computer controlled automatic comprises: the automatic switching program control of 1 pair of small-sized efficient heat accumulating burner capable, burning control, the control of storage heat, the control of combustion unit dome temperature and spent air temperture control.